MNN - Mother Nature Network

Mercury, named for the Roman messenger of the gods, is the smallest planet in our system and the closest to the sun. It's also one of our nearest neighbors — the planet can come as close as 77.3 million kilometers to Earth. And yet, relatively little is known about this small planet. In many ways, it looks like our moon with a cratered surface, rocky body and very little atmosphere. Check out these eight amazing photos of our solar system's tiniest planet, Mercury.